Greyscale is a mysterious disease that keeps popping up in Game of Thrones, and a new set report looks like it will be vitally important to the Season 7 plot for some surprising characters. Spoiler-shy fans, beware.

On the surface, this is not inherently fascinating. It’s standard procedure for a Game of Thrones season to include odd-couple character pairings and road trips. Think Arya and the Hound or Jaime and Bronn or especially Jaime and Brienne.

But this character pairing is different. When we last saw Jorah, he was searching for the cure for Greyscale, the seemingly incurable ailment that turns men into rock-zombies who congregate in the ruined city of Valyria.

To talk about Greyscale is not just to talk about a random disease then. It’s intricately linked to secrets about Valyria’s past, House Targaryen, and the White Walkers.

And since Jon is the newly crowned King of the North and the newly revealed rightful heir to the Iron Throne, linking him with Jorah not only indicates that will we finally get answers about Greyscale, but it will also play a vital role in the wars to come.

Game of Thrones has always had a sprawling tapestry, with disparate plotlines that don’t always seem to connect. But this would connect to Sam’s plot at the Citadel, where he has his own Valyrian steel sword. And especially by bringing back the long lost Gendry to join King Jon and Jorah on this mission, Game of Thrones is beginning to show its cards for its ultimate endgame.

Season 7 will reveal the true nature of Greyscale, which forces us to say a sentence few Game of Thrones fans have uttered in the past: “Wow, I can’t wait for Jorah’s plotline next season!”